Source-backed Working Notes

• Proposal Name: source_backed_working_notes
• Tracking Issue: oceanbase/powercontext#1790
• Status: implementation decision

Decision

PowerContext uses a Source-kind-only design for short-lived working notes. It does not add a durable notes Artifact family. A working note is captured as a ContentSource marked by a server-owned field, with descriptive kind and session metadata. The Source remains addressable by its exact (scope_id, source_type, source_id) identity.

This is distinct from a Memory entry whose kind is also working_note: the latter is an explicit Memory write and is eligible for Memory lifecycle and retrieval. A captured Working Note is evidence only until a caller explicitly uses it in a domain operation.

Hosts capture one through POST /v1/sources/working-notes, the generated Python Client's capture_working_note, or the same MCP tool when exposed. The request requires a caller-stable source_id, host session_id, content, and one of inspection, abandoned_approach, validation, unresolved, or host_context. Replaying an identity with different content remains a Source conflict. A caller may also set a timezone-aware expires_at in the future. An exact replay of an accepted capture returns its original receipt even after expiry; expiry does not weaken capture idempotency.

Working Note classification is a server-owned ContentSource field. The metadata.kind=working_note value is retained as descriptive metadata but is not authoritative by itself. Generic content capture rejects that reserved kind and cannot set the server-owned field. Existing Sources that only happen to carry this metadata value remain ordinary Sources after upgrade and retain their previous generation behavior.

Processing boundary

Working Notes are excluded from automatic Source-window generation. They must not be promoted into Memory, Topic Memory, Experience, or another generated artifact merely because they were captured. Explicit consumers may opt in to the exact Source reference. Handoff evidence resolution opts in because a cited Working Note is still inspectable evidence.

The content is untrusted historical material. It is not an instruction, Skill, prompt policy, or executable tool input.

Retention and access

Working Notes inherit Scope Source authorization. session_id identifies the originating host/session for grouping and future cleanup; it is not an additional authorization boundary. When expires_at is omitted, the note remains active until a future explicit lifecycle action. After the timestamp, new consumers, including Handoff evidence resolution, must treat the note as unavailable.

Expiry is logical: it does not delete or rewrite the immutable Source, which remains readable through the supported Source audit path. Physical purge, session-end cleanup, legal hold, and cross-scope export are separate lifecycle work and are not implemented by this decision.

An exact Source reference remains the evidence identity when a Handoff cites a note. A later cleanup operation must not silently resolve that citation to different content.

Promotion

Promotion is disabled in the initial implementation. A future explicit promotion operation must submit the exact Source reference and pass the owning domain's normal validation. No extractor may infer a durable fact, decision, or constraint solely from the note's presence.

Alternatives rejected

• A new Notes Artifact family duplicates Handoff and Source revision/lineage machinery before the use case is proven.
• Storing notes directly in Memory pollutes durable retrieval with session progress.
• Keeping notes only in host transcripts prevents cross-host evidence resolution.